How to use testStaticMockWithMoInteractions method of org.mockitoinline.StaticMockTest class

Try this:

@RunWith(MockitoJUnitRunner.class)
public class AvailabilityTest {
    @InjectMocks
    @Spy
    private Availability availability = new Availability();

    @Test
    public void testGetStockLevelStage() {
       Mockito.doReturn(expectedLong).when(availability).getStockLevelLimit();
       availability.getStockLevelStage();
    }
}

Here is an article I wrote on Mockito Spying if you need a further read.

You could provide a default Answer in the construction of your mock that always throws an exception. Then every call that is stubbed will act like usual. Everything outside those paths will throw an exception. Something like this:

final String arg = "some arg";
Collection<Object> object = mock(Collection.class, new Answer<Object>() {
    @Override
    public Object answer(InvocationOnMock invocation) throws Throwable {
        throw new IllegalArgumentException("You cannot invoke " + invocation.getMethod() +
                                    " with " + Arrays.toString(invocation.getArguments()));
    }
});
doReturn(true).when(object).add(arg);

object.add(arg); // Goes ok
object.add("azertyuiop"); // Throws the exception

PowerMock implements its own MockMaker which leads to incompatibility with Mockito mock-maker-inline, even if PowerMock is just added as a dependency and not used. If two org.mockito.plugins.MockMaker exist in path then any only one can be used, which one is undetermined.

PowerMock can however delegate calls to another MockMaker, and for then tests are run without PowerMock. Since PowerMock 1.7.0 this can be configured with using the PowerMock Configuration.

The MockMaker can be configured by creating the file org/powermock/extensions/configuration.properties and setting:

mockito.mock-maker-class=mock-maker-inline

Example of using Mockito mock-maker-inline with PowerMock: https://github.com/powermock/powermock-examples-maven/tree/master/mockito2

If I were you, I would simply mock the services A and B and your executors, then inject them thanks to the annotation @InjectMocks as they are fields of your class.

If you want mock the method execute of your Executor, you should rather proceed as next to simply call the method run of the provided Runnable:

doAnswer(
    (InvocationOnMock invocation) -> {
        ((Runnable) invocation.getArguments()[0]).run();
        return null;
    }
).when(serviceAExecutorService).execute(any(Runnable.class));

So basically your test would be something like this:

@RunWith(MockitoJUnitRunner.class)
public class CompletableFutureServiceTest {

    // The mock of my service A
    @Mock
    private ServiceA ServiceA;
    // The mock of my service B
    @Mock
    private ServiceB ServiceB;
    // The mock of your executor for the service A
    @Mock
    private Executor serviceAExecutorService;
    // The mock of your executor for the service B
    @Mock
    private Executor serviceBExecutorService;
    // My class in which I want to inject the mocks
    @InjectMocks
    private CompletableFutureService service;

    @Test
    public void testSomeMethod() {
        // Mock the method execute to call the run method of the provided Runnable
        doAnswer(
            (InvocationOnMock invocation) -> {
                ((Runnable) invocation.getArguments()[0]).run();
                return null;
            }
        ).when(serviceAExecutorService).execute(any(Runnable.class));
        doAnswer(
            (InvocationOnMock invocation) -> {
                ((Runnable) invocation.getArguments()[0]).run();
                return null;
            }
        ).when(serviceBExecutorService).execute(any(Runnable.class));

        ServiceAResponse serviceAResponse = ... // The answer to return by service A
        // Make the mock of my service A return my answer
        when(ServiceA.retrieve(any(ServiceARequest.class))).thenReturn(
            serviceAResponse
        );
        ServiceBResponse serviceBResponse = ... // The answer to return by service B
        // Make the mock of my service B return my answer
        when(ServiceB.retrieve(any(ServiceBRequest.class))).thenReturn(
            serviceBResponse
        );

        // Execute my method
        ServiceResponse response = service.someMethod(
            new ServiceARequest(), new ServiceBRequest()
        );

        // Test the result assuming that both responses are wrapped into a POJO
        Assert.assertEquals(serviceAResponse, response.getServiceAResponse());
        Assert.assertEquals(serviceBResponse, response.getServiceBResponse());
    }
}

I wouldn't use exceptions to test that, but verifications. And another problem is that you can't use when() with methods returning void.

Here's how I would do it:

FizzConfigurator fixture = Mockito.spy(new FizzConfigurator());
doNothing().when(fixture).doWidget(Mockito.anyString(), Mockito.<Config>any()));
fixture.doBuzz("some string");
Mockito.verify(fixture).doWidget("some string", Config.SOMETIMES);

O.K, I got my mistake!!! I've used the @InjectMocks but initialized the same variable in the init() method... So what happened was that mockito injected the mock objects to my variable - but seconds later I ran it over - initializing that very same variable!!!

It's counting your setup as invocations since deeps stubs is not supported in the verification API, and complains on the second call which is:

when(mockSandBox.getSand().doB()).thenReturn(1);

I would skip using RETURNS_DEEP_STUBS and just use another mock:

...
@Mock
SandBox mockSandBox;

@Mock
Sand sand;

@Test
public void should(){
    when(mockSandBox.getSand()).thenReturn(sand);
    when(sand.doA()).thenReturn(1);
    when(sand.doB()).thenReturn(1);
    when(sand.doC()).thenReturn(1);
...

PowerMock 1.6 isn't compatible with Mockito 2.7 (take a look at https://github.com/powermock/powermock/wiki/Mockito#supported-versions)

You should use PowerMock 1.7.0RC2 (or 1.7.0RC3 if 1.7.0RC2 doesn't work), and also use powermock-api-mockito2 instead of powermock-api-mockito.

Note that documentToPojo takes a Class as its second argument. any(Foo.class) returns an argument of type Foo, not of type Class<Foo>, whereas eq(WorkItemDTO.class) should return a Class<WorkItemDTO> as expected. I'd do it this way:

when(mongoUtil.documentToPojo(
    Mockito.any(Document.class),
    Mockito.eq(WorkItemDTO.class))).thenReturn(...);